JPH07233473A - Magnetron sputtering equipment - Google Patents

Abstract

(57) [Summary] [Structure] Magnetron magnetic field generating magnets 11, 12, 14
A gap is provided in a direction orthogonal to the moving direction of the magnets 11 and 14 on the outside. Alternatively, a magnet that cancels the magnetic flux of the magnet at the place where the gap should be provided is brought close to it, or a magnetic material is brought close to absorb the magnetic flux. In addition, the shield located in the moving direction of the magnetron magnetic field generating magnet is insulated from the vacuum container,
The anode is only the shield positioned in the direction orthogonal to the moving direction of the magnetron magnetic field generating magnets 11, 12, 14. [Effect] Since the passage of electrons can be secured, stable discharge can be obtained regardless of the position of the magnet. Therefore, a high plasma density can be secured even when the magnet is located in the center of the target.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film forming apparatus for forming a thin film having a uniform film thickness and film quality on a large area substrate.

[0002]

2. Description of the Related Art When a thin film having a uniform film thickness and film quality is to be formed on a large-area substrate by the magnetron sputtering method, for example, a magnetron magnetic field generating magnet described in JP-A No. 4-80358 is rotated. Or the one for oscillating the magnetron magnetic field generating magnet described in JP-A-4-21775. Since these sputter a large area cathode uniformly, not only the uniformity of the film on the substrate is improved, but also the utilization efficiency of the target is good and the generation of particles (dust) is small.

DC using a DC power supply as a sputtering power supply
In the magnetron sputtering method, the electrons emitted from the target drift on the target or move along the lines of magnetic force and collide with the sputter gas, and then, on the earth shield surrounding the target or on the wall at the same potential as the vacuum container. Flowing. Similarly, when the magnet for generating the magnetron magnetic field is moved, it is necessary to secure the passage of the electron current. In the magnet moving magnetron sputtering system, which uses a large target and moves the magnet to move the plasma region on the target, it is a problem to secure the passage of electron current when the plasma moves to the center of the target. Become. If the substrate is a conductive substance, electrons from the target will flow into the substrate by bringing the substrate to the same potential as the vacuum container, so a path for the electron current can be secured, but if the substrate is an insulator, the electron current It is impossible to pass through the substrate.
Therefore, when an insulator is used for the substrate, when the plasma reaches the center of the target, the place where the electron current should flow, that is, the anode is separated from the place where the electron is emitted. As a result, it is more difficult to form high-density plasma at the center of the target than at the end of the target, and there is a problem that the plasma shape changes depending on the position of the magnet.

[0004]

The plasma on the target has a large effect on the substrate side, such as causing the temperature of the substrate to rise and accelerating the reaction between the film and the sputtering gas. Therefore, if the shape of the plasma changes when the position of the magnetron magnetic field forming magnet is changed, distribution of the film quality on the substrate occurs and the uniformity of the film deteriorates.
In order to ensure the uniformity of the film, it is necessary to prevent the plasma shape from becoming nonuniform even when the magnet is moved. Since the change in the shape of plasma significantly appears as the change in the sputtering voltage, it is necessary to reduce the change in the sputtering voltage when the magnet is moved.

[0005]

In order to solve this problem, the present invention secures a passage for an electron current by providing a gap in a part of a magnetron magnetic field generating magnet located at a position orthogonal to the magnet moving direction. . Even if a gap is not provided in a part of the magnetron magnetic field generating magnet, a magnet having a polarity different from that of the magnetron magnetic field generating magnet is placed close to the magnetron magnetic field generating magnet at a position where the gap should be provided, or a magnetic material is used. Is close to the position where the gap is to be provided. Further, the earth shield part located in the magnet moving direction is insulated from the vacuum container, and the anode is limited to the earth shield part located in the direction orthogonal to the magnet moving direction.

[0006]

Function: Regardless of the position of the magnetron magnet on the target, the electrons flow toward the anode through the gap between the magnets, so that the passage of the electron current can be secured and the discharge is stabilized. as a result,
The plasma is also stable, and the change in sputtering voltage due to the position of the magnetron magnet can be minimized. If the position of the anode is limited to the direction orthogonal to the moving direction of the magnetron magnet, the change in the sputtering voltage can be reduced. As a result, when the magnet is moved, the effect of plasma on the film on the substrate is uniform regardless of the position on the substrate, and the film quality of the thin film formed on the substrate can be made uniform.

[0007]

【Example】

(Embodiment 1) FIG. 1 shows a magnetic pole of a magnetron sputtering apparatus which is an embodiment of the present invention. The outer magnets 11 and 14 and the inner magnet 12 are integrally swung in the direction of arrow 15.
On the target, the outer magnets 11 and 14 and the inner magnet 1
A racetrack-shaped high-density plasma region is formed between the two and the plasma, and as the magnet oscillates and moves, the plasma also moves on the target in a racetrack-shaped manner. The electrons emitted from the target drift in the counterclockwise direction indicated by the arrow 13, and part of the electrons flow from the gap between the outer magnet 11 and the outer magnet 14 to the anode (the same potential as the vacuum container). The remaining electrons continue to drift on the target.
In this embodiment, the gap where the electrons should flow out is located on the extension line of the inner magnet 12 in the longitudinal direction.

(Embodiment 2) An embodiment in which the position of the gap between the outer magnet 21 and the outer magnet 24 is different from that of the first embodiment is shown in FIG. Also in this embodiment, the electrons drift in the direction of arrow 23 and flow to the anode.

(Embodiment 3) FIG. 3 shows an embodiment in which the polarities of the magnetic poles in Embodiment 2 are exchanged. Since the magnetic poles have been exchanged, the drift direction of electrons becomes the direction of arrow 33, and the drift direction is opposite to that in the second embodiment, which is clockwise.
Therefore, the position of the gap where the electrons should flow to the anode is also symmetrical to that in the second embodiment.

(Embodiment 4) FIG. 4 shows an embodiment in which the outer magnet 41 and the outer magnet 44 are linear. In the case of the present embodiment, electrons drift to the anode after drifting in the direction of arrow 43, and almost no electrons drift on the target again. Therefore, the plasma density on the target cannot be increased so much,
Functionally, it is almost the same as that of the second embodiment.

(Embodiment 5) FIG. 8 shows a magnetic pole structure of a conventional magnetron cathode, in which the outer magnet 81 has no gap. Also in this conventional magnetic pole structure, as shown in FIG. 5, the outer magnet 81 in the direction orthogonal to the moving direction 55 of the magnet is
Even if the auxiliary magnets 53 having opposite polarities are brought close to each other, the same effect as that of the embodiment of FIG. 1 can be obtained.

(Sixth Embodiment) Instead of the auxiliary magnet 53 of the fifth embodiment, as shown in FIG.
The same effect as that of the embodiment of FIG. That is, the magnetic flux of the outer magnet 61 in the direction orthogonal to the magnet moving direction 65 may be short-circuited.

(Embodiment 7) FIG. 5 shows an embodiment of the magnetron magnetic field generating magnet of Embodiment 1 in which only the shield positioned in the direction orthogonal to the moving direction is used as an anode. The racetrack-shaped plasma 73 moves on the target 75 in the direction of arrow 74 along with the movement of the magnetron magnetic field generating magnet. The shield 72 located in the moving direction of the magnetron magnetic field generating magnet is insulated from the vacuum container, and electrons emitted from the target 74 do not flow in. The shield 71 located in the direction orthogonal to the moving direction of the magnetron magnetic field generating magnet has the same potential as the vacuum container, and almost all the electrons emitted from the target 74 flow into the shield 71.

A conventional aluminum electrode (size 5 ″ × 15 ″) with a closed electron drift path has two strokes.
When the magnet was oscillated at 60 mm (± 130 mm) and the DC sputtering power source was controlled at a constant power, the sputtering voltage was 350 V and the fluctuation was ± 20 V. When the same test was performed with the magnetic pole of the present invention shown in FIGS. 1, 5 and 6, the sputtering voltage was 340 V and the fluctuation was ± 10 V, and the conventional voltage fluctuation could be reduced by half. The same applies to the embodiments of FIGS. 2 and 3, and FIG.
In the example, the sputtering voltage was 380 V and the fluctuation was ± 10 V. In the embodiment of FIG. 7, the sputtering voltage was 350 V, and the fluctuation could be reduced to ± 8 V.

[0015]

According to the present invention, it is possible to reduce the change in sputtering voltage when the magnet moves.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of magnetic poles of a magnetron cathode according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of magnetic poles of the magnetron cathode according to the second embodiment of the present invention.

FIG. 3 is an explanatory diagram of magnetic poles of a magnetron cathode according to a third embodiment of the present invention.

FIG. 4 is an explanatory diagram of magnetic poles of a magnetron cathode according to a fourth embodiment of the present invention.

FIG. 5 is an explanatory diagram of magnetic poles of a magnetron cathode according to a fifth embodiment of the present invention.

FIG. 6 is an explanatory diagram of magnetic poles of a magnetron cathode according to a sixth embodiment of the present invention.

FIG. 7 is an explanatory diagram of magnetic poles of a magnetron cathode according to a seventh embodiment of the present invention.

FIG. 8 is an explanatory diagram of a magnetic pole structure of a conventional magnetron cathode.

[Explanation of symbols]

11, 12, 14 ... Magnet for generating magnetron magnetic field, 13
… Electron drift direction, 15… Magnet swing direction.

Claims (4)

[Claims] 1. A substrate on which a thin film is to be formed in a vacuum container,
Magnetron sputtering having a target, which is a mass of a substance to be a thin film, and a magnetic field generating means for forming a magnetic field parallel to the target, and having a mechanism for moving the magnetic field generating means with respect to the target. The magnetron sputtering apparatus according to claim 1, wherein a gap is provided in a part of the magnetic field generating means located in a direction orthogonal to the moving direction of the magnetic field generating means. 2. A substrate on which a thin film is to be formed in a vacuum container,
It has a target which is a mass of the substance to be the thin film, and a magnetic field generating means for forming a magnetic field parallel to the target, and has a mechanism for moving the magnetic field generating means with respect to the position of the target. In the magnetron sputtering apparatus, a magnetic field generating means having a polarity different from that of the magnetic field generating means is provided in proximity to a part of the magnetic field generating means located in a direction orthogonal to the moving direction of the magnetic field generating means. Magnetron sputtering equipment. 3. A substrate on which a thin film is to be formed in a vacuum container,
It has a target which is a mass of the substance to be the thin film, and a magnetic field generating means for forming a magnetic field parallel to the target, and has a mechanism for moving the magnetic field generating means with respect to the position of the target. In the magnetron sputtering apparatus, a magnetic material for short-circuiting the magnetic flux of the magnetic field generating means is provided in proximity to a part of the magnetic field generating means located in a direction orthogonal to the moving direction of the magnetic field generating means. Magnetron sputtering equipment. 4. A shield member positioned in a moving direction of the magnetic field generating means and the vacuum container are insulated from each other, and only a shield positioned in a direction orthogonal to a moving direction of the magnetic field generating means serves as an anode. Magnetron sputtering equipment.